Electric system for operating track switches



Jan- 7,`1941- F. H. RICHTERKESSING 2,227,512

ELECTRIC SYSTEM FOR PERTING' TRACK SWITCHES Filed June 50, 1930 Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE ELECTRC SYSTEM FOR OPERATING TRACK SWITCHES 15 Claims.

My invention relates to an electric system for operating track switches, and is particularly adapted to be controlled by an operator on an electric car.

One of the objects of my invention is to supply switch operating current to the system for a predetermined time regardless the position of the car after having once set the system in operation.

Another object of my-invention is a provide means for automatically selecting the position of the track switch from the car through the medium of the motor controller, when thrown to either power on or power off.

Another object of my invention is to prevent the track switch mechanism from being operated to the wrong position by a car after having been initially operated to the correct position.

Another object of my invention is to provide a system which is operable when trolley contactors are engaged successively in one direction only, and which is further arranged so that a car moving in either direction will restore the system to normal after the last of the succession of contactors is engaged.

A still further object is to reduce the magnitude of the arcs; broken at the trolley contactors to a practical minimum.

A still further object of my invention is to provide a system of signal indications for indicating the exact condition and position of the track switch mechanism.

A still further object of my invention is to provide means whereby the first car, after having initially operated the track switch to the desired position, will automatically prevent a following car from subsequently operating the switch until after the first car has passed a predetermined point. Other objects will disclose themselves as the disclosure of my invention is made herein.

My invention resides in a new and novel construction, the combination and relation of the various parts and circuits herein described and disclosed in the drawing accompanying this specication; in which:

Figure 1 is a diagram illustrating the circuits of an electric car that are taken into account in the operation of my invention.

Fig. 2 is a schematic drawing of my invention showing the relations of the various parts and circuits when the system is in a normal condition, that is, prior to an operation for positioning the track switch. The switch tongue, however, may be shown in either of its positions.

As hereinbefore mentioned, it is the object of my invention to provide a system by means of which a track switch is automatically and electrically operated to its straight ahead or curved position, dependent upon the car operator setting the motor controller in the power on or power 5 ofi position. The system utilizes the principle that when the controller is set to the power ou position, no current flows through the motors, and when the controller is set to the power on position, a heavy current flows through the motors'. The flow and non-flow of current is made use of in the operation of the system for selecting the position of the switch tongue. There are other currents flowing through other electrical circuits of the car, which circuits are not under the control of the motor controller, and these must be taken into consideration in designing the system. These circuits are referred to as the auxiliary car circuits and are known as the heat, light and air compressor circuits.

In Fig. 1, the letter W represents a trolley wheel or current collector, and the letter T represents a trolley pole by which the current collector is mounted upon the car. H indicates the heaters, L the lights, J the air compressor, and these, when in operation, together with possibly others, may total a considerable amount of current. The motors for moving the car are indicated by M, and, the controller by which the current to the motors is controlled, is indicated by the letter C. All the circuits for the car are connected to the ground G.

In the preferred embodiment of my invention, which is shown in a normal condition in Fig. 2, P represents a trolley pan or contactor positioned adjacent the trolley wire I, and is so arranged that, when the current collector W comes into engagement with its contact members 2 and 3, it will pass out of contact engagement with the.` trolley conductor I and into contact engagement with the contact members of the trolley contactor P. The trolleycontactor P comprises two laterally-spaced, parallel contact-members 2 and 3, which contact-members are normally insulated ffrom each other and the trolley conductor I, and are so positioned that the current collector will bridge the two when passing thereover.

I also employ a track switch mechanism TM connected to the track switch tongue by an operating plunger PL. The electrically operated mechanism for the tongue comprises two sole noids N and R, one terminal of each solenoid being connected to the ground G through a common conductor 2 I. Reciprocally operating with- 55 in the solenoids in the plunger PL, which plunger is drawn inwardly when the solenoid R is energized, and drawn outwardly when the solenoid N is energized, and, being connected to the switch tongue, moves the tongue to one or the other of its positions. The plunger PL also operates a circuit controller K through aconnecting rod O. The circuit controller K is provided with a common armature A8 operating between two contacts 45 and 41, and the armature A8 is connected to the ground G through wire 48.

I also employ an electrically operated switch RD, which I will term a selective switch as its function is to place one or other of the solenoids l through wire 6, knife switch blade 5 and wire 4.

The coil KL preferably consists of a few turns of heavy wire, as it must withstand a very heavy current flowing therethrough. It must also have its ampere turns so proportioned that it will .operate to raise its switch arm A5, when the controller C is in the power on position and the current collector W in contact engagement with the trolley contacter P, and which will not affect .the armature A5 when the controller is in the power off position. Further, the ampere turns must be so regulated that the current flowing through the auxiliary circuits, which will also ows'through the operating coil KL, will not affect the armature A5, when the current collectorsW engages the trolley contacter P with power oif. Contact member 2 is electrically connected to the trolley wire l at all times via coil KL, and, when the current collector engages the trolley contacter P with power on, current ows from the trolley wire to the contact member 2, through the current collector W, trolley pole T, controller C, meter lVi to the ground G, and, incident to this operation, contact member 3 is electrically connected to the trolley wire I, through the current collector W. The selective switch RD is also provided with two contacts I8 and 22, and a switch arm A5 normally in contact engagement with back contactv i8. Therefore, the selector switch the letters RD is normally set for operating solenoid R, and remains so set, when the collector engages the pan with power off." When the collector engages the contacter Pwith power on, armature A5 engages contact 22, thereby connecting solenoid N for operation. The selector switch RD is 'also'provided with a holding coil D, which coil is connected in series with solenoid N, for retaining armature A5 raised until the operating current flowing to solenoid N is interrupted.

The electrically operated switch RS is provided with an operating coil A having-one of its terminals connected to the contact member 3 of trolley contacter P through wires 25, 2'! and switch blade 25, and its other coil terminal connected to the ground G, through wire 28, the resistance unit RI, wire it, coil S, wire l1, armature A5, back Contactv i8, wire i9, solenoid R, wire 2B, wire 2l. It is not necessary that the operating current for coil A be taken to the ground through the track switch operating soleneid, as it may be taken directly to the ground G without interfering with the functions of the various parts-as required. The resistance of coil A is suilciently high so that only a slight arc takes place, when the current collector W disengages the trolley contacter P. Relay RS is also provided with an armature Ai, which armature is normally out of contact engagement with its front contact i5. The relay RS is also provided with a holding coil S, which coil is connected in series with the switch operating circuit for retaining armature All raised until the ow of switch operating current is interrupted.

The normally-energized retarded-release magnetic-blowout relay RB is provided with an operating coil B having one of its coil terminals connected through wire 34, contact of the normally closed trolley contacter Y, contact strip 3B of normally closed trolley contacter Y, wire 36 to the trolley conductor l, and its other coil terminal connected to armature A2 of relay RL by wire 33. Relay RB is also provided with an armature A3, which armature is normally in contact engagement with its front contact i3. The armature A3 and front contact i3 operate within a magnetic blowout, the construction of which is well known to those skilled in the art. This is symbolically represented by the characters MB. |The retarded-release time-element factor of relay vRB is symbolically represented by BT, and this may be brought about by various well known constructed principles of the art, namely, a brass or copper sleeve placed about the core of the operating coil B or by dash pot arrangement connected to the armature A3.

rThe locking relay RL is provided with an operating coil L and has one of its coil terminals connected to a resistor Ri, through wire 29, and its other coil terminal connected to contact strip 5B of trolley contacter U through wire 3i), and front contact 32 through wire 3l. The relay RL is also provided with an armature A2, which armature is normally in contact engagement with its front contact 32.

The light controlling relayRQ is provided with an operating coil Q and an armature A4. The armature A4 and one coil terminal of its operating coil Q is connected to the trolley conductor l through resistance unit R2, wire l2, wire Il, wire l0, knife switch blade 9 and wire 1. The other coil terminal of the operating coil Q is connected to a common connection 4l) of the indicating lights GL and YL through wire 39. The normally disengaged back contact il of relay RQ is connected to the RLi vlight indication, through wire 42.

The indicating lights GL, YL and RLI are disposed within a suitable housing, and are placed behind colored lenses to give the desired indications.

rlhe uni-directional trolley contacter Z is placed in advance of the' switch operating contacter P, and operates in conjunction with directional relays RE and RF'. The uni-directional trolley contacter Z is provided with two contact members 3A and 5A. These vcontact strips are constructed and arranged so that the current collector W successively connects themto the trolley conductor I upon passing through the contacter. Relays RE' and RF selectively operate according to the direction of travel of the current collector W, and require successive contact engagement of contact strips' 3A and 5A. Relay RE is provided with an operating coil E and has one of its coil terminals connected to the ground G'through the resistance unit Rand wire 55, and its other coil terminal-connected tostrip 5A of trolley 'contacter Z through wire 54 and te one terminal of coil F through wire 53. The relay RE is also equipped with an armature A6 and a normally disengaged front contact I. The armature A6 is connected to the other contact strip 3A through wire 49. Relay RF is provided with an operating coil F' and has one of its coil terminals connected as aforesaid, and its other terminal connected to front contact 5I of relay RE through wire 52. The relay RF is also equipped with an armature A1 and a normally disengaged front contact 53. The front contact 56 is connected to the trolley contactor U through wires 60 and 6 I. The arma- `ture A1 is connected to the trolley conductor I,

through wires 50,' Ill, knife switch blade 9 and wire 1. A more complete description o1" the circuits and disposition of these parts is` presented hereinafter.

The three pole double throw switch SW is so arranged and connected that when it is in one position the switch controlling relays are in circuit with the switch operating contactor P, and when` it is thrown to the other position the relays are disconnected from the trolley contactor P, and the contact member 2 of the trolley contactor P is directly connected to the trolley conductor I, through wires 1, 8, knife switch blade 5 and wire 4.

As the current collector W approaches the switch operating contactor P in the direction of the arrow AR, it rst engages contact strip 3A of trolley contactor Z. As this contact engagement is completed no operation of the selective relay RF can result as its operating circuit is open at the armature A6 of relay RE. As the wheel continues its course of travel, and engages contact strip 5A of trolley contactor Z, a circuit is completed through the operating coil E of relay RE. This operation of relay RE will not affect the operation of the switch operating circuits as a successive operation of relays RE and RF must occur.

If the current collector initially engages the switch operating contactor P with power off, the operating coil KL of the selective switch RD is not sufficiently energized to raise its armature A5, and the normal selection of armature A5 is retained. As the current collector comes into contact engagement with the contact strip 3 of trolley contractor P, a circuit is completed through the normally deenergized operating coil A of relay RS. This circuit is completed from the contact strip 3, through wire 25, knife switch blade 26, wire 21, operating coil A of relay RS, wire 23, resistance unit RI, wire I6, low resistance coil S, wire I1, armature A5 of relay RD, back contact I8 of relay RD, wire I9, switch operating solenoid R, wire 20, wire 2 I, to the ground G. As the armature AI of relay RS is brought into contact engagement with its normally disengaged front contact I5 a circuit is completed to the switch operating solenoid R of the track switch TM, from the trolley conductor I, through wire 1, knife switch blade 9, wire It, wire II, armature A3 df relay RB, normally engaged front contact I3 of relay RB, wire I4, armature AI of relay RS, front contact I 5 of relay RS, wire I6, holding coil S ci relay RS, wire I1, armature A5 of relay RD, back contact I8 of relay RD, wire I9, solenoid R, through wire 2U, wire 2| to the ground G. Instant to this operation, the normally energized relay RL instantly releases its armature A2 through the application of a shunt circuit effected by the engagement of contact I5 and armature AI of relay RS. The releasing of armature A2 of relay RL, opens the circuit of the operating coil B of relay RB, since the relays RB and RL Vhave their operating coils B and L normally connected in series. This normal circuit is completed from the trolley conductor I, through wire 36, contact strip 3B of trolley contactor Y, contact 35 of trolley contactor Y, wire 34, coil B of relay RB, wire 33, armature A2 of relay RL, normally engaged front contact 32 of relay RL, wire 3|, operating coil L of relay RL, wire 29, resistance unit RI, wire I6, low resistance coil S, wire I1, armature A5 of relay RD, back contact I8 of relay RD, wire I9, solenoid R, wire 2li, wire 2I to the ground G. As hereinbefore mentioned, the releasing of armature A2 by relay RL, opens the operating circuit of coil B of relay RB, but the armature A3 of relay RB is retarded in its release, as heretofore described. Aiter a predetermined time armature A3 disengages front contact I3 of relay RB within the magnetic blowout MB, and the current flowing to the switch operating solenoid R is interrupted. Relays RB and RL remain in their deenergized positions irrespective of the length of contact engagement of the current collector W with the Contact member 3 of the trolley contactor P, and until the current collector continues its course of travel and comes into contact engagement with the contact strip 5B of the trolley contactor U, wherein a circuit is established for re-energizing operating coil L of relay RL. rlhis circuit is completed from the trolley conductor I, through the current collector W, contact strips `5B of trolley contactor U, wire 39, solenoid L of relay RL, wire 29, resistance unit RI, wire I6, holding coil S of relay RS, wire I1, armature A5 of relay RD, contact I8 of relay RD, wire I9, solenoid R, wire 2D, wire 2l to the ground G. The energization of operating coil L of relay RL raises armature A2 into contact engagement with front contact 32. However, the operating coil B of relay RB is not reenergized until after the current collector W disengages contact strip 5B oi trolley contactor U, wherein the normally energized circuits for relays RB and RL are reestablished. In the event of multiple car-train operation, trolley contactor U is replaced by two trolley contactors X and XI, as shown in dotted lines. The purpose of this arrangement is to assure the switch operating circuit being held open until after the cars have cleared the switch point. rlhe function of the normally closed trolley contactor Y, located between the switch operating contactor P and the unlocking trolley contactor U, is to assure the opening of the circuit for coils B and L, of relays RB and RL, before the car enters the switch point. This is a very desirable feature, especially when one or more cars follow closely over the switch point, since without the use oi this trolley contactor, it would be possible to have a car enter the switch point without the circuits being properly electrically locked.

It is often desirable to permit cars to trail through the switch point in the opposite direction, and, with the ordinary apparatus heret fore employed, the circuits are left open. The directional sensitive trolley contactor Z is incorporated in the system so that the passage of the current collector in one direction will not affect the relay L of the switch operating control, but the passage of the current collector W in the opposite direction will restore the system to a. normal operating condition. It can be seen that the current collector W moving in the direction opposite to that indicated by the arrow AR, first engages trolley contactor U, and energizes relay RL, for restoring the system te a normal condition. After this, the collector W .engages the auxiliary locking contacter Y, and opens the circuit of relays RL and RB, for opening the switch operating circuit. Therefore, when the switch operating contacter P is subsequently engaged, the switch solenoids are not energized, as their circuits are open. However, when the current collector W engages the trolley contacter Z, the circuits are restored to their normal operative conditions. This operation is affected by the successive contact engagement of contact strip 5A and contact strip 3A.

The light indio-ations of the system are so arranged that, When the switch is thrown Ito one position and electrically locked, a yellow light YL indicates, and, when the switch is thrown to .the opposite position and electrically locked, a green light GL indicates, and if the switch is operated to a mid-position, which would be a dangerous condition, neither the green or yellow lights indicates and a red light RLI is displayed to warn of this dangerous condition. This is brought about through the applicati-on of the relay RQ, used in conjunction with the switch cir-cuit controller operated by the movement of the switch plunger.

There are, of course, modications and arrangements of parts which may be made from that shown in the above disclosure and which will still fall within .the scope of my invention.

I claim:

l. In a track-switch operating system compris-- ing, in combination, a track-switch; a solenoid for operating the said track-switch; a trolleyconductor; a normally-open circuit including the trolley-conductor and solenoid; a Vehicle-actuated device normally electrically-cennected to the said trolley-conductor; vehicle-controlled means for closing the said normally-open circuit; and vehicle-responsive means, controlled by electrically-disconnecting the said device from the said trolley-conductor, fer rendering .th-e said circuit inoperative by the said vehicle-controlled means.

2. In a track-switch operating system comprising, in combination, a track-switch; actuating solenoids for operating the said track-switch selectively; a branched operating circuit for energizing the said solenoids selectively to provide for the aforesaid selective operation of the trackswitch; a circuit-changer for connecting selectively the branches of .the said operating circuit to their corresponding solenoids .to provide for the aforesaid selective energization thereof; a normally-open switch included in .the said operating circuit; means for closing the said normally-open switch; means for retaining the said normallyopen switch closed comprising an operating coil of relatively low resistance included in the said operating circuit; a normally-closed switch included in the said operating cir-cuit; a normallyenergized circuit including an operating coil and normally-closed Contact of a stick relay, and an operating coil of the said normally-closed switch; and means, operating in response to the Iclosing of the said normally-open switch, for de-energizing the said normally-energized circuit te open the normally-closed contact of the said stick relay; and means for reclosing the contacts of the said stick relay tere-energize the said relay circuit.

3. A .track-switch operating system comprising, in combination, a track-switch; electro-magnetic operating means for Ithe said track-switch; an operating circuit therefor; :a switch-operating contacter; normally-de-'energized relay-means,

operatively connected .to the said switch-operating contacter and energized in response to an actuation thereof, for closing the said operating circuit; a normally-energized relay-means for opening directly the said operating circuit; means, operating in response to the closing of the said operating circuit, for de-energizing the said normally-energized relay-means, to render thereby inoperative the said electro-magnetic operating means to subsequent energizations of the said normally-de-energized relay-means; a restoring contacter; and means, operatively cennected to the said restoring contacter and operating in response to an actuation thereof, for reenergizing the said normally-energized relaymeans.

4. In a track-switch operating system comprising, in combination, a track-switch; an actuating solenoid therefor; a trolley-conductor; a normally-open switch-operating circuit including the said trolley-conductor and actuating solenoid; a switch controlling the said operating circuit; vehicle-responsive means for closing the switch controlling the said circuit, .thereby to energize ythe said solenoid; a protective device for rendering the said operating circuit inoperative te energize the said solenoid; vehicle-responsive means adapted te be operated successively by a vehicle moving in one or the opposite direction, for operating the said protective device; means operatively associated with the first and last oi the said vehicle-responsive devices, for restoring the said protective device to normal to render thereby operative the said operating circuit, when either of the said first and last devices are operated by a vehicle moving in the said one direction; and means operatively associated with the said last of the devices, for restoring ythe said protective device to normal to render thereby operative the said operating circuit, when the said last device is operated by a vehicle moving in the said oppesite direction.

5. In a track-switch operating system, the combination of an electrically-operated track-switch; an operating circuit therefor; a normally-energized relay for directly controlling the said operating circuit; a second normally-energized relay for controlling the rst mentioned relay; a normally-d'e-energized relay for closing .the said oper-ating circuit; means for energizing the last mentioned relay; means, responsive to the closing of the said operating circuit for de-energizing the said second relay, thereby to de-energize the rst mentioned relay means; and means for re-energizing ythe said second relay means,

6. An automatic locking system for electricallyoperated track-switches comprising, a trackswltch; electro-magnetic means for operating the said track-switch; a Itrolley-wire; a plurality of vehicle current-collectors at a distance from each other and co-eperative with the said trolley-wire; a switch-operating contacter and a restoring contacter, each positioned adjacent the trolley-wire at a distance from each other and actuatable by the said current collectors; a normally-open switch-operating circuit including the said electro-magnetic means and the .trolley wire; a nermally-energized main relay having a normallyclosed con-tact thereof included in the said operating circuit; a normally-energized locking-relay controlling the energization of the normally-energized main-relay; a control-relay, operating in response to an actuation ef the said switch-operating contactor, for closing the said switch-operating circuit; means, operating in response to the aforesaid operation oi the said control relay, for de-energizing the said normally-energized lockingrelay, :thereby `to rie-energize the said normallyenergized main-relay for rendering inoperative 5 the said electro-magnetic means as soon as the said normally-closed contact of the normally-energized main relay opens in response tothe operation of the last mentioned means; and means, operating in response to an actuation lof the said l restoring contacter, for ree-energizing the aforesaid normally-energized locking relay; the said electro-magnetic means being thus rendered inoperative until the first of said current collectors, after having actuated the said switch-operating 151 contactor, actuates the said restoring contacter.

'7. In an automatic locking system of the character set forth in claim vo comprising, an auxiliary locking-contactor positioned adjacent the said trolley wire, at a point between the afore- 2O said switch-operating and restoring contactors,

and actuatable by the aforesaid current collectors; and means, operating in response to an actuation of the said auxiliary locking-contacter, when the said iirst of the current-collectors ac- 25 tuates the said restoring contacter after a subsequent current-collector has actuated the said switch-operating contacter, for de-energizing the aforesaid normally-energized locking-relay; the said electro-magnetic means being thus rendered 30lfurther inoperative, as aforesaid, until the said subsequent current collector, after having actuated the said auxiliary locking-contacter, actuates the said restoring contactor.

8. In a track-switch operating system compris- 35 ing, in combination, `a track-switch; a solenoid for operating the said track-switch; an operating circuit for the said solenoid; a normally-open relay-switch and a normally-closed relay-switch electrically connected in series and included in 40 the said operating circuit; a normally-de-energized operating-coil, Which, when energized, closes the said normally-open relay-switch, and a normally-energized relay-coil, which, when deenergized, opens the said normally-closed switch; 45 means for energizing the said normally de-energized relay-coil; and means, operating in response to the aforesaid energization ci the said normallyde-energized relay-coil, for de-energizing the said normally-energized relay-coil, thereby to open 50 the said normally-closed relay-switch and to render the said circuit ineffective to subsequent closings of the said normally-open relay-switch.

9. An automatic locking-system for electrically-operated track-switches comprising, a 55 track-switch; electro-magnetic means for operating the said track-switch; a trolley-wire; a plurality of vehicle current-collectors spaced a distance from each other and cooperative with the said trolley-wire; a switch-operating contacter 60 and a restoring contacter, each positioned adjacent the trolley-wire at a distance from each other and actuatable by the said current collectors; an operating circuit including the said electro-magnetic means; a iirst normally-energized 65 relay having a normally-closed contact thereof included in the said operating circuit; a second normally-energized relay controlling the energization ci the rst relay; a third normally-deenergized relay having a normally-open Contact 70 included in the said operating circuit; a iirst control-circuit including an operating coil of the third relay and the said switch-operating contactor, for energizing the .said third relay to close the normally-open switch thereof, when a collec-` 75 tor actuates the said operating-contacter; a second control-circuit including the operating coils of the first and second relays and a normallyclosed contact of the second relay; means, operating in response to the closing of the normallyopen switch of the third relay, for cle-energizing 5 the said second relay, thereby to open the said second control-circuit; a third control-circuit including the operating coil of the said second relay and the said restoring contacter, for re-energizing the said second relay, when a collector actuates the said restoring contactor, thereby to re-close the said second control-circuit, whereby the said electro-magnetic means is rendered inoperative until the first of said collectors, after having actuated the said switch-operating contactor, actuates the said restoring contactor.

l0. In a track-switch operating system comprising, in combination, a track-switch; electromagnetic means for operating the said trackswitch; a trolley-wire; a switch-operating contactor and a restoring-contactor, positioned adjacent the said trolley-wire; a normally-open circuit including the said electro-magnetic means and the trolley-wire; a normally-open switch and a normally-closed switch electrically connected in series and included in the said normally-open circuit; an operating-coil for each of the said switches; a lock-control relay; a normally-closed circuit including an operating-coil and normallyclosed contact of the said lock-control relay and an operating coil of the said normally-closed switch; a control-circuit including the operatingcoil of the said normally-open switch and the said switch-operating contacter; and a restoring circuit including the coil of the said lock-control relay and the said restoring contacter.

ll.. A track-switch operating system comprising, in combination, a track-switch; actuating solenoids for operating the said track-switch selectively; an operating circuit having branches for energizing each solenoid selectively; a circuitchanger for connecting selectively the said solenoids in the corresponding branches of the said operating circuit to provide for the aforesaid selective energization thereof; a normally-energized relay having a normally-closed contact thereof included in the said operating circuit for controlling directly the energizaton of the solenoid connected in either branchof the said operating circuit; a normally-open switch for closing the said operating circuit to energize the solenoid connected in either branch thereof; means for closing the said normally-open switch;

a relay coil included in the said operating circuit, and energized by the flow of solenoid current in the said operating circuit, for holding the normally open switch in closed condition; and means, operating in response to the closing of the said normally open switch for de-energizing the said normally energized relay, thereby to open directly the said operating circuit for de-energizing the solenoid selectively connected in either branch of the said operating circuit.

12. A track-switch operating system comprising, in combination, a track-switch; electromagnetic means for operating the said trackswitch; a normally-open circuit including the said electro-magnetic means; a normally deenergized relay having a normally-open switch thereof included in the said circuit; a rst normany-energized relay having a normally-closed Switch thereof included in the said circuit; means for energizing the said normally de-energized relay to close the said normally-open switch, and thereby to close the said normally-open circuit;

a second normally-energized relay, which, when de-energized, de-energizes the said first relay; and means, operating in response to the closing of the said normally-open circuit, for de-energizing the said second relay, thereby to de-energize the said rst relay.

13. A track-switch operating system comprising, in combination, a track-switch; electromagnetic means for operating the said trackswitch; a normally-open circuit including the said electro-magnetic means; a normally-open switch for closing the said circuit; a rst normally energized relay having a normally-closed switch thereof included in the said circuit; a second normally-energized relay; a normally-closed circuit including the operating coils of the said rst and second relays and a normally-closed switch of the said second relay; and means, operating in response to the closing of the said normally-open switch, for de-energizing the said rst and second relays, thereby to open the said normally-open circuit including the normallyclosedv switch of the first relay, and to open the normally-closed circuit including the normallyclosed switch of the second relay.-

14. A track-switch operating system comprising, in combination, a track-switch; electromagnetic means for operating said track-switch; a normally-open circuit including the said electro-magnetic means; a normally-open switch for closing the said circuit; means for closing the said normally-open switch; a rst normallyenergized relay having a normally-closed switch thereof included in rthe said circuit; a second normally-energized relay, which, when de-energized, de-energizes said rst relay; and means, operating in response to the closing of the said normally-open switch, for de-energizing the said second relay.

15. A track-switch operating system comprising, in combination, a track-switch; electromagnetic means for operating the Said trackswitch; a normally-open circuit including the said electro-magnetic means; a normally deenergized relay having a normally-open switch thereof included in the said circuit; a rst normally-energized relay having a normally-closed switch thereof included in the said circuit; means for energizing the said normally de-energized relay to close the said normally-open switch, and thereby to close the said normally-open circuit; a second normally-energized relay, which, when de-energized, de-energizes the said rst relay; means, operating in response to the energization of the said normally de-energized relay, for deenergzing the said second relay, thereby to deenergize the said rst relay; and timing means, operatively associated with the normally-closed switch of the said rst relay, for delaying the opening of the said normally-closed switch for a predetermined period of time after the de-energization of the said rst relay.

FRANK H. RICHTERKESSING. 

